Dental operative instrument



Feb. 9, 1932. c. c. HALLOWELL. 1,844,913

' DENTAL OPERATIVE INSTRUMENT Filed Jan. 26, 1929 FIG 1Q 'of said handle.

Patented F ch. 9, 1932 UNITED STATES PATENT OFFICE CLIFTON G. HALLOWELL, OF LANSDOWNE, PENNSYLVANIA, ASSIGNOR TO THE S. S. WHITE DENTAL MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA DENTAL OPERATIVE INSTRUMENT Application filed January 26, 1929. Serial No. 335,208.

My invention relates particularly to that class of dental operative instruments that comprises, along slender handle having a relatively short tapering shank terminating in a blade or other suitable device best adapted to cutting, scraping or otherwise subjecting to the desired treatment the object being operated upon. a Y i It will be obvious that the operating tool it end of such an instrument should be as near as practicable to the axial plane of the handle I to obtain the best working conditions when said instrument is being thrust forward or drawn backward in the direction of the axis It has been heretofore pointed out, however, that when lateral thrust is brought to bear, the working position of the actuating cutting edge, point or surface of such an operative instrument should be in a plane which intersects the point of pressure of the forefinger, and the point of rest on the thumb of the operator, and it has also been proposed that the shank be so bent or deflected as to dispose such cutting edge, point or surface in the intersecting plane of pressure and rest and thereby so balance the instrument that it will seat its cutting edge squarely against the surface being operated upon and willnot thereafter tend to turn or twist in the operators hand while being thus used.

The principal objects of my invention are to provide an operative instrumenthaving its operative point of pressureand point of rest disposed in a plane which as nearly approximates the axial plane of the handle as prac: ticable so that the cutting edge, point oractuating surface of its tool form may be disposed in or near to'the-axialplaneof the 1 4 handle and will seat itself upon the object being operated upon without tending to twist or turn said handle in the hand of the operator, and affording an instrument in which all directional working pressures will best harmonize,

e Other objects of my invention are to provide an operative instrument having in its handle a depressionaffording a flattened surface of maximum breadth serving to provide a substantial bearing or rest abutment for to the tip of the'foreiinger of the operator and against which said 1 forefinger may be thrust to obtain rigid grip" upon said instrument.

My invention includes an operative instrument having its handle provided with one or more bends forming suit-able depressions arranged to receive the forefinger or thumb of the operator and serving to dispose the pressure and rest positions as close as practicable to the axialplane of the instrument handle.

Specifically stated, the form of my invention as hereinafter described comprises an operative instrument having in its handle a depression or depressions forming regions of contact for the forefinger and thumb of the operators hand and having a cutting edge, point 01' actuating surface which is directed toward or disposed substantially in a plane which intersects points in the surfaces of said depressions nearest the axis of said handle.

My invention also includes all the various novel features of construction and arrangement as hereinafter more definitely specified.

In the accompanying drawings, Figure 1 is a side elevational view of an operative instrument constructed in accordance with my invention, shown held'in the hand of the operator and having its cutting edge in actuating position upon a tooth projecting from the surrounding gum, which is shown in section; Fig. 2 is a side elevational view of the operative instrument shown in Fig. l and having indicated thereon the axial and working planes; Fig. 3 is a top plan view of the operative instrument shown in Figs. 1 and 2; and Fig. 4 is a side elevational view of an operative instrument embodying a slight modification of the invention.

In said figures, the operative instrument shown in Figs. 1, and 3 comprises the handle 1, shank 2, and the terminal tool form, which may be a cutting edge 3, a point, or other operative surface of suitable contour, said handle being shown hexagonal, as commonly formed, but obviously may be otherwise polygonal or cylindrical.

The instrument illustrated is arranged to be held in the hand 4 of the operator, as shown in Fig. 1, and is provided with the cutting edge 3 preferably for the purpose of scraping the surface of the artificial tooth 5, which, as shown in said figure, has its root 6 embedded in the gum 7, indicated in section. Said instrument is conveniently provided with the depression 9 in its handle 1 affording an elongated, broad, flat surface 10, best illustmted in Fig. 3, terminating forwardly in the upwardly curved surface 11.

As shown in Figs. 1 and 2, the depression 9 closely approximates the axial plane 12 of the instrument handle 1 so that when held in the hand of the operator, the inner surface of the distal section 15 of the forefinger 16 of the operator rests upon the flattened surface 10 while the tip 17 of said forefinger 16 rests against the curved surface 11 which is curved to conform to the operators finger-tip.

The inner or rearward end portion19 of the instrument handle 1 rests upon the medial section 20 of the operators thumb 21, while the inner surface of the distal section 22 of the thumb 21 bears against the side of the instrument handle 1 and serves the purpose of retaining the instrument handle in position to rest upon the thumb 21, while being borne against by the forefinger 16.

Referring to Fig. 2, it will be observed that a plane 25 intersecting the point of rest 26 and the point of pressure 27, as indicated by the arrows, closely approximates the axial plane 12 of the instrument handle 1 at the region of the cutting edge 3 or forward extremity of the instrument tool form, so that said cutting edge 3 will not only he in the plane 25 inter secting the point of rest 26 and the point of pressure 27, but it will be disposed in close proximity to the axial plane 12, so that when said cutting edge 3 is actuated upon the surface of a tooth, or other object being treated or operated upon, its position will be ideally located for all pressures whether forward or backward axially of the handle or whether the pressure he lateral with respect to said handle or a combination of said pressures, so that the instrument handle will not tend to turn or twist in the hand of the operator when pressure is brought to bear thereon.

As shown in Fig. 4, the instrument handle 31 has its shank 32 terminating in the cutting edge or tool 33 and said handle is provider with the bend 35 providing a depression 36 disposed upwardly of said handle with respect to the cutting edge, and affording a pressure point 37 for the forefinger of the operator, and said handle is also provided with the bend 39 affording a depression 40 in the lower surface of said handle disposed toward the rearward end thereof and extending in a direction opposite to the depression 36 at the forward end of said handle and affording a point of rest 41 for the thumbof the operator.

In this form of my invention, the axial plane 42 of the instrument handle intersects the cutting edge 33 of said instrument and is tangent to the depressions 36 and 40.

My invention is advantageous in that it provides an operative instrument that affords a firm grasp by the hand of the operator at regions so alined with its operating blade as to maintain its stable balance when forced into operative contact with the object being operated upon, and thereby relieves the operator of any effort due to the tendency of such instruments to twist or turn in the hand.

I do not desire to limit my invention to the precise details of construction and arrangement as herein set forth, as it is obvious that various modifications may be made therein without departing from the essential features of my invention as defined in the appended claims.

Having thus described my invention, I claim:

1. An operative instrument comprising a handle of the type illustrated having a depression near its forward end and provided with a shank deflected laterally and terminating in an operative tool form which is directed toward the axial plane of said handle from the side in which said depression is disposed, said depression bein independent of said shank, and locating t e operative part of the tool in a plane which passes through the depression and the operative partof the tool and closel approaches the axis of the handle while the alance of said instrument is maintained.

2. An operative instrument comprising a handle, a shank and a tool form, said handle being provided with a depression near its forward end serving as a seat for engagement of the finger of the operator, so that a plane passing through the working edge of said tool form and touching the innermost surface of said depression and cutting the opposite surface of said handle near its end remote from said shank at a point where it rests on the operators thumb, will be so closely coincident with the true axis of the handle that the operative part of the tool form closely approxihandle.

mates the axial plane of said handlewhile the Working balance of said instrument is main tained.

3. An operative instrument comprising a 5 handle having a position of pressure and rest respectively on the opposite surfaces thereof and terminating in a tool form, and in which the tool form, the point of pressure and point of rest are disposed in the axial plane of said In Witness whereof, I have hereunto set my hand this twenty-first day of January, A. D..

CLIFTON C. HALLOWELL. 

